What to know about drug-resistant epilepsy and eligibility for surgical treatment

Over 3 million people in the United States are affected by epilepsy, a brain condition that causes recurring seizures. About 30% have what’s called drug-resistant epilepsy, also referred to as refractory or intractable epilepsy, where anti-seizure medications don’t work.

Although the condition is fairly common, it’s important to address uncontrolled seizures, because they could result in serious injury or sudden unexpected death in epilepsy (SUDEP).

Over time, seizures can lead to physical injury and even affect memory and emotions. And uncontrolled seizures can impact aspects of your daily life, such as driving and employment.

When is epilepsy considered drug-resistant?

According to the International League Against Epilepsy (ILAE), epilepsy must meet certain criteria to be considered drug-resistant, including:

• An individual fails to become (and stay) seizure-free after two medications.
• The seizure medications prescribed are appropriate for the seizure type and were tried alone and together with other seizure medications.

How is drug-resistant epilepsy diagnosed?

When someone’s epilepsy doesn’t respond to standard treatment with medication or lifestyle changes, it’s important to get further evaluation at an epilepsy center. The Ohio State University Wexner Medical Center is a Level 4 comprehensive epilepsy center that provides the highest level of epilepsy care available. Our epilepsy care team, which includes epileptologists, neurosurgeons, radiologists, neuropsychologists and other epilepsy providers, has the expertise to diagnose patients with drug-resistant epilepsy and help find the most effective way to treat their seizures.

The first step is getting an accurate diagnosis. Our epilepsy care team will collect detailed information from you and perform a comprehensive evaluation. You’ll likely also need to have diagnostic tests, which may include:

• Electroencephalogram (EEG) – a short brain wave recording to look for activity that indicates the likelihood of epilepsy.
• Magnetic resonance imaging (MRI) – uses a strong magnetic field and radio waves to create detailed images of the brain’s structure to allow a physician to evaluate whether structural lesions or other abnormalities may be causing your symptoms.
• Single photon emission computed tomography (SPECT) – a type of scan that detects blood flow changes in the brain and shows the “hotspot” in the brain where the seizure starts.
• Positron emission tomography (PET) scan – small amounts of radioactive material are injected into the patient’s vein, allowing us to study the brain’s use of oxygen or sugar (glucose).

If you’ve had any of these tests before, they may need to be repeated to get the most detailed diagnosis.

Some people might need another evaluation in our epilepsy monitoring unit, so that the care team can see seizure activity in a controlled clinical setting. Continuous video-EEG monitoring is used in this process to record both behavior and experiences during a seizure and the corresponding electrical activity in the brain.

Once we have a diagnosis and it’s confirmed that medication alone isn’t effective to treat your seizures, we’ll talk with you about advanced treatment options, such as surgery or neuromodulation therapy.

What are the surgical options for drug-resistant epilepsy?

Whether you’re a candidate for surgery or neuromodulation therapy depends on where your seizures are coming from (the seizure focus) and whether the focus is in a region of the brain where it can be safely removed.

Types of epilepsy surgery

• Disconnection surgery – where the surgeon cuts or disconnects the brain tissue responsible for your seizures
• Laser ablation – a minimally invasive procedure where we target and burn away the specific lesions in the brain that are causing your seizures
• Lesionectomy – when a specific lesion and some surrounding brain tissue is removed to stop it from triggering seizures
• Lobectomy – a procedure that completely removes part of your brain where your seizures start

If the seizure focus can’t be removed safely through one of these surgeries, then neuromodulation therapy is another option that’s proven to be effective in reducing or eliminating seizures. These therapies include:

• Deep brain stimulation (DBS) – involves implanting small electrodes within specific regions of your brain. The electrodes are then connected to a pacemaker-like device positioned beneath your skin on your chest wall. The device generates low-intensity electrical impulses that regulate abnormal seizure activity in the brain.
• Vagus nerve stimulation – similar to DBS in that it uses the same type of device in your chest wall. Seizures are reduced by regular, mild pulses of electrical energy sent to your brain via a wire around the vagus nerve, which travels up your neck to your brain.
• RNS neurostimulation – involves implanting a small device in the brain that monitors electrical activity and provides stimulation to help regulate abnormal patterns before a seizure occurs.

These therapies are approved by the U.S. Food and Drug Administration for drug-resistant epilepsy.

What research is Ohio State doing in the area of epilepsy?

We have several ongoing research studies, but one of the most notable is using sonic waves to remove an epilepsy focus. This is a non-invasive therapy that could be an alternative for people with drug-resistant epilepsy who aren’t candidates for traditional surgery.

This type of therapy could also benefit those who suffer from uncontrolled epilepsy with tonic-clonic (or grand mal) seizures that involve a sudden loss of consciousness, followed by a stiffening of the body and jerking movements.

Although it’s still being researched, this epilepsy treatment offers a future method for controlling seizures without surgical incisions or direct contact with the skull or brain.